Introduction to Testfully Markup Language

Testfully Markup Language, shortened as TFML, is a config file format, written in TOML (Tom's Obvious, Minimal Language). It's a way to configure API requests, collections, folders, environments, vaults, cookies and more in a format that is easy to read, write and understand by humans, machines and LLMs.

TFML is a relatively new format in Testfully, released first in August 4th, 2025. Our plan is to make it the primary way to define API requests, collections and other resources in Testfully, replacing the current JSON format when importing, exporting and sharing collections. Below is an example TFML file that defines a simple HTTP request to https://httpbin.org/anything endpoint:

method = "POST"
url = "https://httpbin.org/anything"

# attach one or more query params to the request
[params]
name = "Testfully"
version = "1.0"

# attach one or more headers to the request
[headers]
Content-Type = "application/json"

# send a JSON body with the request
json = """
{
  "message": "Hello, Testfully!"
}
"""

Today, Testfully Offline workspaces can host TFML-based collections and requests. In the coming months, we will be adding support for TFML in other parts of Testfully, including Testfully CLI.

Why TFML?

That's a great question! As Testfully evolves, we found the need to have a format that could be easily understood by both humans and machines, while also being flexible enough to accommodate various types of API requests and configurations. Traditional JSON format, while widely used, can be verbose and is not as user-friendly as TFML, hence the need for a new format.

Why TOML?

We chose TOML as the base for TFML because it is the simplest config file format out there, it's very easy to learn and understand, and it has a great code editor support with features like syntax highlighting and autocompletion. This enables developers to inspect and edit TFML files with ease, while also having a wide range of libraries and tools available for parsing and manipulating TOML files to roll out custom integrations and tools.

What's next?

Check out the TOML in 5 minutes to learn more about the format and how to use it effectively in your projects. TFML files are valid TOML files, so you can use any TOML editor or library to work with them.

Learn more about TFML

To learn more about TFML file format for API requests, collections, folders, environments, vaults, cookies and more, check out the following sections: